1. Rounding and estimating: Upper and Lower Bounds (sig figs)
Silent
Teacher
Intelligent Practice
Narration
Your Turn
300 has been rounded 2 significant figures.
Calculate the upper bound.
Calculate the lower bound.
Write down the error interval.
Practice

2. Worked Example
Your Turn
300 has been rounded 2 significant figures.
Calculate the upper bound.
Calculate the lower bound.
Write down the error interval.
300 has been rounded to 3 significant figures.
Calculate the upper bound.
Calculate the lower bound.
Write down the error interval.
@mathsmrgordon

3. Worked Example
Your Turn
7 has been rounded to 1 significant figure.
Calculate the upper bound.
Calculate the lower bound.
Write down the error interval.
8 has been rounded to 2 significant figures.
Calculate the upper bound.
Calculate the lower bound.
Write down the error interval.
@mathsmrgordon

4. Value Rounded to Place value + / - Lower Bound Upper Bound
Error Interval
400
1 significant figure
3 significant figures
2 significant figures 40 4
0.4
0.3 30
0.03
@mathsmrgordon

5. Value Rounded to Place value + / - Lower Bound Upper Bound
Error Interval
400
1 significant figure
100
+ / - 50
350
450
350 ≤ x < 450
3 significant figures
Whole
+ / - 0.5
399.5
400.5
399.5 ≤ x < 400.5
2 significant figures
Tens
+ / - 5
395
405
395 ≤ x < 405 40
39.5
40.5
39.5 ≤ x < 40.5 4
Hundredths
+ /
3.95
4.05
3.95 ≤ x < 4.05
3.5
4.5
3.5 ≤ x < 4.5
0.4
Tenths
0.35
0.45
0.35 ≤ x < 0.45
0.3
0.25
0.25 ≤ x < 0.35 30
29.5
30.5
29.5 ≤ x < 30.5
0.03
+ /
0.025
0.035
0.025 ≤ x <
@mathsmrgordon